Mechanically-actuated microfluidic valve

Abstract

A mechanically-actuated microfluidic valve. The valve comprises an inlet port; an outlet port; a thermal bend actuator; and a valve closure member cooperating with the actuator. Actuation of the thermal bend actuator causes movement of the closure member, thereby regulating a flow of fluid from the inlet port to the outlet port.

1. A mechanically-actuated microfluidic valve comprising:
 an inlet port; 
 an outlet port; 
 a weir positioned between said inlet and outlet ports; 
 a pair of opposed thermal bend actuators, each of said actuators comprising: 
 an active beam comprised of a thermoelastic material; and 
 a passive beam mechanically cooperating with said active beam, such that when a current is passed through the active beam, the active beam heats and expands relative to the passive beam, resulting in bending of the actuator; and 
 a valve closure member cooperating with said actuators, such that actuation of said actuators causes movement of said closure member relative to a sealing face of said weir, thereby regulating a flow of fluid from said inlet port to said outlet port, wherein said closure member is comprised of an elastomer fused or bonded to the active beams of said actuators and bridges a space therebetween. 
 
     
     
       2. The microfluidic valve of  claim 1 , wherein said active beam is fused to said passive beam. 
     
     
       3. The microfluidic valve of  claim 1 , wherein said active beam defines a bent current path extending between a pair of electrodes, said electrodes being connected to control circuitry for controlling said actuator. 
     
     
       4. The microfluidic valve of  claim 1 , wherein said thermoelastic material is selected from the group consisting of: titanium nitride, titanium aluminium nitride and vanadium-aluminium alloys. 
     
     
       5. The microfluidic valve of  claim 1 , wherein said passive beam is comprised of a material selected from the group consisting of: silicon oxide, silicon nitride and silicon oxynitride. 
     
     
       6. The microfluidic valve of  claim 1 , wherein at least said actuator is defined in a MEMS layer of a silicon substrate. 
     
     
       7. The microfluidic valve of  claim 6 , wherein said substrate comprises control circuitry for controlling said actuator, said control circuitry being contained in at least one CMOS layer of said substrate. 
     
     
       8. The microfluidic valve of  claim 1 , wherein said inlet port and said outlet port are defined in a MEMS layer of a silicon substrate. 
     
     
       9. The microfluidic valve of  claim 1 , wherein said inlet port and said outlet port are defined in polymeric microfluidics platform. 
     
     
       10. The microfluidic valve of  claim 1 , wherein said closure member is comprised of polydimethylsiloxane (PDMS). 
     
     
       11. The microfluidic valve of  claim 1 , wherein said actuation causes open or closing of said valve. 
     
     
       12. The microfluidic valve of  claim 1 , wherein said actuation causes partial opening or partial closing of said valve.